New Findings about ACL Repair May Help Athletes Plan Timing of Surgery

After an anterior cruciate ligament (ACL) repair, some patients have trouble getting their full quadriceps muscle strength back. This study checked whether the width of the tendon used to replace the torn ligament is linked with muscle weakness after ACL repair.

ACL repair can be done by taking a piece of the quadriceps tendon and using it to replace the damaged ACL. Doctors measured the width of patellar tendons used in 540 patients. They measured quadriceps muscle strength before and after the ACL repair.

The researchers thought it was likely that patients with small patellar tendons and a weak quadriceps muscle wouldn’t be able to get their full quadriceps strength back. In the short run that’s exactly what they found. Patients with large tendons had better strength in the first three months after surgery.

By the end of two years, the tendon size didn’t make a difference in muscle strength. Patients with good muscle strength before the operation had good postoperative strength as well. The authors also reported the following findings:

  • Poor quadriceps strength before the operation keeps the patient from getting strength back quickly after ACL repair.
  • Surgery should be scheduled when the patient has full motion, normal walking, and no knee swelling.
  • Patients with small tendons and a weak quadriceps muscle should work on getting better quadriceps strength before the ACL repair.
  • Doctors should use a different graft source when patients have narrow quadriceps tendons and a weak quadriceps muscle. Using a graft from the other leg is a good option.